1. Field of the Invention
The present invention relates to an ink jet printer.
2. Description of the Related Art
For safety reasons, the ink used in ink jet printer is usually a water-based ink. To prevent clogging of nozzles, water-based ink that evaporates slowly must be used. However, such ink also dries slowly after printing so that printed sheets are difficult to handle. Because water-based ink runs easily, there has been a problem of different color inks running together and mixing during color printing. Also, precision of printing drops when recording sheets wrinkle, expand, or stretch. Attempts have been made to reduce severity of these problems by improving the recording sheets. However, these methods require production of special sheets that are expensive. Recording devices for rapidly drying the ink on the printed sheets are described on page 35 in the February 1994 issue of Hewlett-Packard Journal (not prior art). Actual methods described include heating printed sheets directly after printing to dry the printed sheets. The printed sheets are heated by streams of hot air, by radiant heat, or by heated platen rollers.
However, all these methods require detection of the temperature of the printed sheet and control of energization of the heat source. Safety measures such as for preventing overheating and generation of smoke and fire are necessary. Normally heating efficiency is low. However, power consumption is not always low. Generally a long waiting period is required for the heat source to heat up after the power is turned on until when printing is possible.